In an effort to reduce both their lighting and household cooling expenses, many homeowners have begun replacing their halogen light bulbs with cooler-burning, energy efficient LED (light-emitting diode) bulbs. The major obstacle to a straight one-for-one replacement scheme is that LED bulbs and halogen bulbs often have different dimensions and diameters. Finding a replacement bulb in the correct size and base configuration is more than half the battle in swapping an LED for a halogen bulb.
Remove the halogen bulb you wish to replace from its fixture or lamp. Note its wattage and light output--usually measured in lumens or candela (candle power).
Visit any retailer selling LED bulbs with your old halogen in hand. Explain that you intend to replace your existing halogen bulb with a compatible LED bulb with the same type of base. Request assurances that if you buy a bulb that won't fit in your fixture, you can return it for a refund or exchange.
Examine the LED bulbs to find a suitable replacement. Pay particular attention to the base and shape of the LED. If possible, remove it from the packaging and compare it side-by-side with your halogen bulb. As an example, a medium or standard-base halogen bulb should be matched to an LED with the same base type. This also applies to intermediate, candelabra and mini-candelabra bases.
Match the light output of new LED bulb to the halogen bulb it is replacing. For instance, a 20-watt halogen bulb may put out from 200 to 300 lumens, LED lights marketed as replacements for a 20-watt halogen may only put out between 100 and 200 lumens, according to the study "Performance of Halogen Incandescent MR16 Lamps and their LED Replacements," conducted by the Pacific Research Laboratory for the U.S. Department of Energy in 2008. Light-output equivalency is usually marked on the packaging.
Install the LED into your existing lighting fixture or lamp. If it fits, you're finished. If it does not, return it to the retailer for a refund or exchange it for another LED which does fit.
LED bulbs may cost more initially than a comparable halogen bulb.